Re: Tomcat JDBC Connection Pool interfaces to PostgreSQL... - Mailing list pgsql-jdbc
| From | Dave Cramer |
|---|---|
| Subject | Re: Tomcat JDBC Connection Pool interfaces to PostgreSQL... |
| Date | |
| Msg-id | CADK3HHJH9EaHWtMuoDz1M_Vbc79ph2bEmkWnbX1meociDwyXCg@mail.gmail.com Whole thread Raw |
| In response to | Tomcat JDBC Connection Pool interfaces to PostgreSQL... (Eric Neron <eneron@e-djuster.ca>) |
| Responses |
Re: Tomcat JDBC Connection Pool interfaces to PostgreSQL...
Re: Tomcat JDBC Connection Pool interfaces to PostgreSQL... Re: Tomcat JDBC Connection Pool interfaces to PostgreSQL... Re: Tomcat JDBC Connection Pool interfaces to PostgreSQL... |
| List | pgsql-jdbc |
it would appear that tomcat is not returning the PgConnection object.
I just wrote this as a test:
public void testConnectionUnwrapPGDataSource() throws SQLException {
PGSimpleDataSource dataSource = new PGSimpleDataSource();
assertNotNull(dataSource);
dataSource.setDatabaseName("test");
dataSource.setServerName("localhost");
dataSource.setPortNumber(5432);
Connection connection = dataSource.getConnection("test","test");
assertNotNull(connection);
Object v=connection.unwrap(PGConnection.class);
assertNotNull(v);
assertTrue(v instanceof PGConnection);
}
and it works fine.On 17 May 2016 at 14:40, Eric Neron <eneron@e-djuster.ca> wrote:
I am currently working using the Tomcat JDBC Connection Pool (http://tomcat.apache.org/tomcat-7.0-doc/jdbc-pool.html) which we plan to use in our Java Web application in order to streamline server resources usage associated to supporting our PostgreSQL connections (i.e., minimize the number or connections required).I am using the following jar files to support my work:tomcat-jdbc.jarpostgresql-9.4.1208.jre7.jarAlthough most of it seems to be working fine so far, I am hitting issues when I try to "cast" the connection the pool is returning to me (a ProxyConnection) into either a PGConnection or BaseConnection. I need those in order to access either of the following PostgreSQL "advanced/internal" methods:- addDataType () (PGConnection)- CopyManager () (BaseConnection).The Tomcat documentation suggests to extract the native connection by using the following method:Connection pgConnection = ((javax.sql.PooledConnection) conn).getConnection ( );Although this does not fail, using a debugger, I can see that pgConnection is really anorg.postgresql.jdbc.PgConnection (not an org.postgresql.PGConnection), and there is not way it seems that I can bridge between the two... even by using:pgConnection.unwrap ( PGConnection.class );I am just wondering if this issue is caused by the fact that I use theorg.apache.tomcat.jdbc.pool.DataSource to instantiate my Connection Pool.Browsing through the list of choice given to me to determine where the DataSource class is imported in my Java code, I can see:javax.sql.DataSource (which I have seen can give one access to PGConnection from one of my research on the Web - http://stackoverflow.com/questions/27898632/how-to-cast-jdbc4connection-to-pgconnection), though if I select it, it tells me that this is an abstract Class that I cannot instantiate from!Similarly, another StackOverlflow page (http://stackoverflow.com/questions/36986653/cast-java-sql-connection-to-pgconnection) suggests using the following code:PGConnection pgConnection = dataSource.getConnection().unwrap(PGConnection.class);but again, if I try this, I get the following SQLException: "Not a wrapper of org.postgresql.PGConnection"(in fact, it turns out that this is exactly the same solution as the "Tomcat solution" I explained above).I am running out of alternatives... Any ideas?
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